Control of Pepper Weevil with Azadirachtin and Synthetic Insecticides on Bell Pepper, Spring 1994

Abstract

Abstract Greenhouse raised bell pepper seedlings were transplanted on 7 Feb, 12 inches apart between plants in single rows on raised beds covered with black polyethylene film mulch. Beds were prepared by fumigation with 33/67 chloropicrin/methyl bromide at 220 lbs/acre and fertilized with a bottom mix of 800 lbs/acre of 5-16-8 and a top mix of 1000 lbs/acre of 19-0-30. Rows were 240 feet long on 12 foot centers and watered by subirrigation. Two rows were divided into 4 blocks of 120 feet, each block consisting of 6, 20-ft plots. Plants were sprayed weekly with a fungicide rotating between a mix of 3.0 lbs Kocide DF plus 1.0 lb/acre Maneb 80 W and Bravo applied at 32 oz/acre. Six treatments were assigned to each block in a randomized complete block design with 4 replications. Applications were made on 9 consecutive weeks starting 14 Mar using a 12 tank sprayer equipped with a diaphragm pump powered by a gasoline engine. The sprayer was mounted on a small trailer pulled by a 4-wheel drive Suzuki ATV at 2 MPH. Spray was distributed by a single row boom consisting of 2 side drops with 2 nozzles each and one over the row nozzle for a total of 5 nozzles. Albuz ATR® “red” ceramic tipped nozzles were used at 80 PSI of pump pressure for a delivery rate of 35 gal/acre. An adjuvant, ASPA 80® (Amway Corp.), was added to treatments containing Lorsban, Vydate and Karate at 0.05% v/v and NeemGuard® at 0.14% v/v for the Azadirachtin 4.5%. Following a pretreatment count which yielded an average of 0.13 weevils per 10 plant sample per block, adult weevils were counted weekly on 10 randomly selected plants per plot and bud and fruit drop caused by weevils was evaluated. Aphid infestations on these plants were evaluated by visually rating on a scale of 1 to 5 beginning 5 Apr. Aphid parasitism was evaluated beginning on 25 Apr by counting mummies and nonparasitized apterous aphids from 9 leaves per plot treated with Lorsban and control. Ten plants from each plot were harvested and graded for marketability on 9 May. Nonmarketable fruit was further graded into 3 categories based on type of damage.